Karachi Airport 'Revenge' Attack Leaves 28 Dead

At least 28 people have been killed after gunmen disguised as police guards attacked a terminal at Pakistan's Jinnah international airport in Karachi.

Militants armed with automatic weapons, a rocket launcher, suicide vests and grenades stormed the airport and were involved in an intense six-hour firefight with the airport's security force, police, paramilitaries and commandos.

Ten of the dead were the attackers, according to Pakistan's paramilitary Rangers.

Also killed were 11 airport security staff, civilian airport employees and four Pakistan International Airlines (PIA) staff. Another 26 people were injured.

The Pakistani Taliban claimed responsibility for the attack saying it was in revenge for their late leader Hakimullah Mehsud, who was killed in a US drone strike in November.

"We have yet to take revenge for the deaths of hundreds of innocent tribal women and children in Pakistani air strikes," spokesman Shahidullah Shahid said.

"It's just the beginning, we have taken revenge for one (Mehsud), we have to take revenge for hundreds."

He also dismissed the possibility of a new round of peace talks with the Pakistan government.

Television footage showed what appeared to be a major fire and plumes of smoke floating across the runway near parked aircraft.

Pakistan's military spokesman Major General Asim Bajwa said after the operation had ended: "Update: Area cleared. No damage to aircraft, fire visible in pics was not plane but a building, now extinguished. All vital assets intact."

Maj Gen Bajwa added that ammunition, rockets and grenades were recovered from the dead attackers.

"Precautionary sweep after daylight. Airport will be cleared by midday for operations, handed back to CAA (Civil Aviation Authority)/ASF (Airport Security Force). Pakistan Zindabad (long live Pakistan)!" he tweeted.

Heavy gunfire and multiple explosions had been heard coming from the airport as authorities scrambled to secure the area.

The terminal targeted by the militants was said to be used for VIPs and cargo. Passengers were evacuated and all flights diverted.

The attack will raise fresh concerns about Pakistan's security situation, and questions about how militants were able to penetrate the airport which serves one of the world's biggest cities.

Karachi has been the site of frequent militant attacks in the past.

Elsewhere, a suspected Taliban suicide bomber rammed a truck into a Pakistan military checkpoint on the border with Afghanistan, killing four soldiers.